1. Field of the Invention
The present invention relates to a pixel structure and a repairing method thereof. More particularly, the present invention relates to a pixel structure, which is easily repaired, and a repairing method thereof.
2. Description of Related Art
Thin film transistor liquid crystal display (TFT-LCD) has become the main stream in display market due to its characteristics such as high display quality, low power consumption, and no radiation. A typical TFT-LCD includes a TFT array substrate, an opposite substrate, and a liquid crystal layer between the foregoing two substrates. The TFT array substrate includes a substrate, a plurality of pixel structures arranged as an array on the substrate, scan lines, and data lines. The pixel structure includes a TFT, a pixel electrode, and a storage capacitor, wherein the TFT may be an a-Si TFT or a poly-Si TFT. Generally speaking, a scan signal transmitted by the scan line turns on the corresponding TFT, the image signal transmitted by the data line is then transmitted to the corresponding pixel electrode through the TFT so that the pixel electrode controls the liquid crystal thereon. Moreover, the pixel structure can maintain a good display quality with the assistance of the storage capacitor thereof.
FIG. 1A is a schematic diagram of a conventional pixel structure, and FIG. 1B is a cross-sectional view of the pixel structure in FIG. 1A along line A-A′. Referring to both FIG. 1A and FIG. 1B, the conventional pixel structure 100 includes a scan line 110, a data line 120, a TFT 130, a storage capacitor 140, and a pixel electrode 150. The TFT 130 is electrically connected to the pixel electrode 150. The storage capacitor 140 is composed of an upper electrode 142 and a common line 160 (bottom electrode), and the storage capacitor 140 is formed on the common line 160 (Cst on common).
During fabricating processes, when short circuit between the upper electrode 142 and the common line 160 in the storage capacitor 140 is induced by particles or defects in the dielectric layer 146 caused by other factors, leakage in the storage capacitor 140 can be caused. In other words, the leakage may prohibit the pixel structure 100 from being charged effectively while the TFT 130 is turned on and may cause abnormal charge leakage while the TFT 130 is turned off. Besides, during the fabricating processes, when short circuit between the common line 160 and the pixel electrode 150 is induced by particles, the pixel electrode 150 can not receive the control signal properly, so that display abnormality is caused. In short, if short circuit occurs between the upper electrode 142 and the common line 160 or between the common line 160 and the pixel electrode 150 during fabricating processes, the pixel structure 100 cannot be repaired effectively. Accordingly, the display quality of the LCD is deteriorated.